2.5 ton air handler and no heat kit

I have a goodman 2.5 ton ARUF3030 air handler in my attic.
There is a knock out on the front for 1 or 2 breakers.
Do I need to add a breaker if I'm not adding a heat kit?
I have a dedicated 15amp line running to my attic.

Is it possible to use that line for the blower motor?

I'd hate to have to run a new line up from the basement.
If I have to, I would run the line up next to the copper line set.

2.5 ton air handler and no heat kit

I bought a double pole switch to mount.
Does it need to be mounted on the air handler?

The wire is about 2 feet short to mount to the front of the AH.
I could mount it on the back or to a close beam in the attic.
I can buy a junction box and extend the line to reach the front if that is what is required but if not I'd be a happier.